The target is the creation of nanocomposites that exhibit similar morphological structures as polyurethane elastomers. With one strategy, novel elastomeric materials consisting of inorganic nanoparticles (hard phase) and polyetherols of high molecular weight (soft phase) were generated. A second strategy focused on the incorporation of nanoparticles within classic polyurethane elastomers. The nanoparticles act as fillers on the one hand, on the other hand they are covalently linked to the polymeric network. For the first strategy, the desired functional groups, the methods of synthesis and mechanisms for cross-linking were defined. If polyetherols of high molecular weight (≥ 1000 g mol-1) are used as the soft segment, a cold crystallization phenomenon of the polyurethane elastomer was noticed between -40 and 25 °C, which was assigned to the polyetherol component. By additionally using diols or triols of low molecular weight, the phenomenon was reduced and eliminated, respectively. If low-molecular diols are added, phase separation (hard and soft phase) occurs, which was shown by TEM and AFM. The hard phases were larger as expected (0,4 to 1,65 µm), what means that crystalline superstructures (spherulites) are present. If multi-functional polyols were incorporated as well, the size of the spherulites was limited. For creating novel elastomeric materials, the aza-Michael-reaction of polyetherols (functionalized with acrylate groups) and silica nanoparticles with surface-bonded amine groups was chosen. Functionalization of the polyetherols was successful. However, the aza-Michael-reaction was only possible for reaction partners of low molecular weight, not for the high-molecular components. It is stated that the desired polymeric network can not be generated by aza-Michael-reaction of the components, which were defined at the beginning. Unmodified silica-nanoparticles and silica-nanoparticles with surface-immobilized amine groups were incorporated within polyurethane elastomers. A processing instruction for drying of the nanoparticles, the dispersion of the agglomerates and the incorporation within fluid components of high molecular weight was developed. For stoichiometric calculations, the number of amine groups per gramm silica nanoparticles was determined by different methods. Polyurethane elastomers with unmodified silica nanoparticles did not show a change of the dynamic-mechanical performance. The covalent linkage of functionalized silica nanoparticles within polyurethane elastomers optimized the mechanical stability of the nanocomposite at elevated temperatures, if the agglomeration of the nanoparticles was limited. If dispersed functionalized silica nanoparticles are incorporated, the same dynamic-mechanical performance of the composite is achieved as when having classic hard phases inside the polymer, which are created by diols of low molecular weight.